This project is directed at the isolation, purification and characterization virus-induced membrane antigens (MA) from cells infected with or transformed by the Epstein-Barr virus (EBV) or Herpesvirus saimiri (HVS). A number of membrane proteins have now been identified in Raji cells superinfected with the P3HR-1 virus strain. In contrast, only two glycoproteins have been identified in cells transformed with the B-95 strain, only one of which is shared with the P3HR-1 virus. Monoclonal antibodies have now been prepared against both EBV and HVS glycoproteins. Studies are now ongoing to (1) purify the major EBV glycoproteins to homogeneity and to determine their role in immunity to EBV; and (2) to prepare monoclonal antibodies to other EBV and HVS proteins to determine the similarities and differences between virus isolates.